Collision prevention system for vehicles

ABSTRACT

The invention relates to a system for preventing collisions of an automobile with obstacles. Sensors mounted in the automobile detect the area surrounding the vehicle. The signals of said sensors are evaluated by a data processing device in order to calculate the available obstacle-free driving space. Other sensors additionally detect the position of all movable vehicle parts (e.g. a trailer) and the dynamic parameters of the current driving situation (e.g. speed, steering angle, etc.). Based on said data, the driving speed required during the following time intervals in order to continue driving is calculated in advance by the data processing device and compared with the actually available obstacle-free driving space that has been detected. Said comparison provides early forecast regarding a possible collision. The driver is warned of a possible collision danger by corresponding warning devices and can consequently react in time. In critical situations (e.g. high driving speed), direct interventions in the control of the vehicle by the data processing device can take place to assist the driver.

CROSSREFERENCE TO RELATED APPLICATION

This application claims the benefit of PCT/EP02/04918 filed on May 4,2002 and German patent application 101287925 filed on May 8, 2001.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention is concerned with the field of automotive engineering. Inparticular, the invention relates to safety systems for preventingcollisions.

2. Description of the Related Art

Such systems are specifically significant for vehicles which are lesseasy to steer into critical situations owing to their size, their weightand to a certain extent complex design (for example, a plurality ofaxles, trailers, containers, etc.).

These vehicles are, for example, trucks (rigid vehicles, semitrailersand trailer vehicles), buses, articulated vehicles and other vehicles(for example recreational trailers), in which the problem arises thatexisting overhangs in various regions of the vehicle (rear, front,corner edges and superstructures) swing out when turning andmaneuvering. In addition, depending on the type of vehicle, a pluralityof regions of the vehicle cannot usually be satisfactorily seen from thedriver's position so that owing to “dead angles” the driver isfrequently unable to monitor swinging out—for example by looking in themirror—and notice, for example, during a maneuver, when such regions ofthe vehicle are coming too close to obstacles, and react appropriately.As a result, in tight driving situations there is a risk of collidingwith obstacles and other road users, which may result in serious injuryto persons and severe damage to property.

Typical situations in which the described problems occur are presentedbelow:

a) Risk of Collisions in the Front Region

In particular, vehicles with a large front overhang (distance betweenfront axle and the front of the vehicle) swing out a very long way whenturning or maneuvering and must also move out to a great extent in verynarrow streets. As a result, the front of the vehicle moves over acorrespondingly large radius, and in particular side regions of thefront can quickly impact against obstacles (see FIG. 1). Even whenreversing in order to park or performing reversing maneuvers, the frontof the vehicle moves in a circular arc shape (locked front wheels) sothat there is also the risk of side regions of the front being involvedin a collision (see FIG. 2). This risk is increased further as whenreversing the main attention of the driver is of course directed at therear region of the vehicle in accordance with the direction of travel.

b) Risks of Collisions in the Rear Region

In a corresponding way, in the case of vehicles with a large overhang atthe rear (distance between the rear axle and rear), there is a risk ofcollision specifically of the side regions of the rear both whenperforming maneuvers moving forward and when performing reversingmaneuvers (see FIGS. 3 and 4). In particular in the case of vehicleswith trailers, semi-trailers or superstructures (for example avehicle-mounted rotational crane) these risks of collision areparticularly pronounced.

c) Risks of Collision with Attached Trailers, Semi-Trailers, etc.

Specific problems arise in vehicles with trailers, semi-trailers orsuperstructures. In such vehicles, the front of the attached part of thevehicle swings out in the form of an arc when turning or maneuvering inthe forward direction and reverse direction so that there is a risk ofcollision in critical driving situations (see FIGS. 5, 6, 7).

d) Risk of Collision of the Side Regions of a Vehicle

The side regions of a (relatively long) vehicle can also collide withobstacles in a small maneuvering space (see FIGS. 8 and 9).

The situations described show that the problems of preventing collisionsas comprehensively as possible are relatively complex. Systems in whichdistance messages are issued are known. In such systems, the criticalregions of a vehicle are monitored by devices (for example ultrasonicsensors, video cameras) which sense when obstacles are approached. Whena predefined distance from the obstacle is undershot, the driver iswarned, for example, by means of optical or audible signals. However,these systems can detect obstacles and distances in good time only insimple driving situations. For this reason, owing to the vehicle's ownmovement, warnings are issued too late (or incorrectly) so that as aresult of the, under certain circumstances, high chronological dynamicsof the driving situation, there is hardly the possibility any more forthe driver to react appropriately in good time.

In WO 03/001471 a system is described for avoiding collisions betweenvehicles and obstacles. Therein the spatial environment of theautomobile is surveyed via vehicle sensors and the data derivedtherefrom is supplied to a data processing unit for computing the areafree of obstacles. Other sensors are supplementally used to sense theorientation and position of all moveable vehicle components, as well asdynamic parameters of the instantaneous driving condition. From thesedata, in the data processing unit the space required for the next timeinterval of continuation of the vehicle travel is calculated in advanceand compared with the actual existing obstacle conditions. Thiscomparison provides an early prediction of a possible collision. Incritical situations it is possible, as an aid to the vehicle operator,to make direct input to the vehicle controls via the data processingunit.

U.S. Pat. 5,602,542 A1 describes a system for assisting vehicleoperators during the parking process. By using ultrasonic sensors in thevehicle chassis, a distance profile relative to the vehicle body, and ofthe objects lying closest thereto, is produced. Therein, the contour ofthe vehicle body is stored in a memory unit. In a similarly organizedmemory the distancing profile is recorded. In this manner, by the directcomparison of the memory contents with the aid of a microprocessor, therelative distance between the vehicle body and an object in theenvironment can be continuously determined during parking of thevehicle.

SUMMARY OF THE INVENTION

The invention takes this prior art as a starting point. It is based onthe object of developing an improved system for preventing vehicles fromcolliding with obstacles.

This object is achieved by means of the method as claimed in claim 1 andthe apparatus for carrying out the method having the features of claim8. Further details and advantageous refinements emerge from thesubclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention will be described in greater detail onthe basis of an exemplary construction of an inventive device. FIG. 1shows vehicles with a large front overhang (distance between front axleand the front of the vehicle) swing out a very long way when turning ormaneuvering and must also move out to a great extent in very narrowstreets. As a result, the front of the vehicle moves over acorrespondingly large radius, and in particular side regions of thefront can quickly impact against obstacles (see FIG. 1). FIG. 2 showseven when reversing in order to park or performing reversing maneuvers,the front of the vehicle moves in a circular arc shape (locked frontwheels) so that there is also the risk of side regions of the frontbeing involved in a collision (see FIG. 2). This risk is increasedfurther as when reversing the main attention of the driver is of coursedirected at the rear region of the vehicle in accordance with thedirection of travel. FIGS. 3 and 4 show in a corresponding way, in thecase of vehicles with a large overhang at the rear (distance between therear axle and rear), there is a risk of collision specifically of theside regions of the rear both when performing maneuvers moving forwardand when performing reversing maneuvers (see figs 3 and 4). Inparticular in the case of vehicles with trailers, semi-trailers orsuperstructures (for example a vehicle-mounted rotational crane) theserisks of collision are particularly pronounced. FIGS. 5, 6 and 7 showspecific problems arise in vehicles with trailers, semi-trailers orsuperstructures. In such vehicles, the front of the attached part of thevehicle swings out in the form of an arc when turning or maneuvering inthe forward direction and reverse direction so that there is a risk ofcollision in critical driving situations (see figs 5, 6, 7) FIGS. 8 and9 show the side regions of a (relatively long) vehicle can also collidewith obstacles in a small maneuvering space (see figs 8 and 9).

FIG. 10 shows schematic views of the required driving space using theexample of a tight bend in a chronological sequence (t₀, t₁, t_(n)).

FIG. 11 is an illustration of the existing driving space of the samesituation according to FIG. 10.

FIG. 12 shows a comparison of the required driving space and existingdriving space in accordance with the driving situation at the time t₁(according to FIG. 10).

DETAILED DESCRIPTION OF THE INVENTION

The system according to the invention for preventing collisions detectssituation parameters which are different at a particular time so thatthe risk of a collision can be sensed in good time. On the basis ofthis, collision-preventing measures are then taken. The operation of thesystem can be divided here into individual regions:

a) Determination of the Required Driving Space

A significant component of the system is to determine the requireddriving space, which differs depending on the maneuver. The requireddriving space is the volume in space which is “passed through” inchronological succession as the vehicle travels. This includes, inparticular, also the space which is required when turning andmaneuvering as a result of the swinging out of overhangs. FIG. 10 showsin schematic exemplary form the spatial positions of a truck at thetimes t₀, t₁, t_(n) while going through a tight bend. By incrementallysuperimposing the chronological sequence of the positions it is thuspossible to illustrate the total driving space required for the drivingmaneuver.

In order to avoid collisions, the system according to the inventiondetermines sections of the required driving space chronologically inadvance from various data items by calculation in a data processingdevice (computer, microprocessor).

These data items are, on the one hand, the dimensions of the vehicleincluding the dimensions of further parts of the vehicle, such astrailer, semitrailer, superstructures, etc. In addition to the sizeinformation there are structural details (position of axles, position ofthe support point, etc. of the trailer coupling, etc.) as these alsodetermine the moving out of parts of the vehicle.

In addition to these (generally constant) values, information relatingto the instantaneous position of moving parts of a vehicle (steeringangle, angle between the trailer and traction engine, etc.) whichchanges during the journey and therefore has to be continuously updatedis required. In order to acquire this data, appropriate sensors(measuring sensors, position pickups, etc.) have to be present on thevehicle and their signals have to be passed on to the data processingdevice.

An essential factor for preventing a collision is to calculate inadvance as precisely as possible the driving space which is required infuture (for further travel). For this purpose, in addition to theaforesaid data, various dynamic values of the driving situation (speed,shifting of gear speed, engine speed, brake values, etc.) also have tobe acquired and included in the calculations. For the continuous sensingof these dynamic values, appropriate sensors whose data is transferredto the data processing device are necessary.

The required driving space which is taken up by the vehicle (includingparts of the vehicle) when the travel continues is then calculated as afunction of all this data.

b) Determination of the Existing Driving Space

The existing driving space is a spatial region without obstacles whichis available for the vehicle to travel safely without collisions. Thisdriving space is generally determined by the road profile and isadditionally restricted by immovable obstacles (road boundaries, trees,houses, parked vehicles, etc.), and on the other hand is changed bymoving obstacles and road users (vehicles, pedestrians, etc.). Dependingon the events on the road, the existing driving space changes here moreor less dynamically. FIG. 11 shows this situation of an existing drivingspace which changes over time (t₀, t₁, t_(n)).

In order to prevent collisions, the dimensions of the existing drivingspace must be determined and included in calculations of the dataprocessing device. For this purpose, initially the spatial surroundingsof the vehicle have to be sensed. Various means are used for this, forexample, GPS (Global Positioning System), digital maps (stored in thedata record of the data processing device or capable of being retrievedby a wire-free connection to fixed computers), optical and otherradiation sensors (visible light, infrared, radar), distance andmovement sensors (for example ultrasonic sound, laser, etc.). Inconjunction with video cameras, it is also possible to use moderntechniques for recognizing images (computer evaluation of video signalsfor recognizing objects) in order to identify obstacles. For complexsensing of surroundings as precisely as possible, a plurality of thespecified means are preferably combined here. The data which is suppliedby these devices is transmitted to the data processing device andevaluated there in order to calculate the dimensions of the existingdriving space. Thus, a virtual image can be created, for example as agrid model of the existing driving space.

As, on the one hand, the position of the existing driving space changescontinuously whenever the vehicle itself moves, and on the other handthe dimensions can also change as a result of moving obstacles, thiscalculation of the existing driving space has to be continuouslyupdated. Depending on the current speed of the driver's own vehicle butalso of other moving obstacles (for example oncoming passenger cars), itmay be necessary for the time interval t₁−t₀ between two successiveoccasions when the changing existing driving space is sensed to be inthe region of a fraction of a second.

c) Predicting Collisions by Comparison of Required Driving Space andExisting Driving Space

In order to detect at an early point an imminent collision, a comparisonis carried out between the previously calculated required driving spaceand the existing driving space which is actually sensed at a given time.This comparison is carried out by means of corresponding calculations bythe data processing device. If the required driving space which iscalculated in advance exceeds the limits of the existing driving spacethere is a risk of a collision, that is to say whenever the vehicle(including parts of the vehicle such as trailers, etc.) is in theprocess of leaving the existing driving space if the journey continueswithout change.

As the driving situation (position of the vehicle, moving obstacles,etc.) changes continuously, these comparison calculations over time (t₀,t₁, . . . t_(n)) are repeated continuously with updated data relating tothe existing driving space or required driving space. Ideally,continuous monitoring for a collision is carried out during the entirejourney.

As numerous measurement processes during which inaccuracies may alsooccur, are carried out by means of a number of different sensors inorder to sense both the required driving space and the existing drivingspace, it is necessary to carry out the collision forecasting calculatedfrom this data with safety regions relating to the spatial conditionsand their change over time. For example, the required driving spacewhich is calculated in advance can be enlarged with safety distancesand/or the sensed existing driving space can be correspondingly reduced.Depending on the dynamic development of the driving situation(locomotion of the driver's own vehicle, changes in position of otherroad users) these safety distances can also be adapted dynamically.

All the necessary calculations can be carried out in the vehicle itselfby means of an appropriately powerful on-board data processing device.Alternatively, the signals of the detectors and sensors which arelocated on the vehicle can be transmitted for calculation purposes via awire-free connection to a fixed data processing system and afterevaluation there the results can be transmitted back to the vehiclewhere the corresponding reaction is then triggered. A combined system isalso possible in which a first data processing system in the vehicle isconnected in wire-free fashion to a fixed data processing system.

d) Preventing Collisions

If there is a risk of collision, the system carries out a series ofmeasures according to an incremental catalog of measures. If there issufficient time to prevent the collision through customary drivingmaneuvers, warning signals which cause the driver to intervene areappropriate at first. These warning signals may be issued audibly(striking sounds/tones but also through voice outputs, in which casespecific instructions, for example relating to the place on the vehiclein question or else action recommendations are also possible), optically(for example, by means of light), visually (for example, by means ofgraphic representations of the vehicle and the obstacle on appropriatedisplays), or else haptically (for example, a vibration, shaking of thesteering wheel). If the remaining time is not sufficient for anappropriate reaction by the driver, the system brings about a directintervention in the control of the vehicle, for example, emergencybraking or counter-steering of the vehicle in order to return to theexisting driving space. Furthermore, the size of the required space maybe reduced by automatically reducing the contours of the vehicle (forexample, folding in the side mirrors, retracting the antennas, loweringspoilers, etc.; changing the ride control, in order to reduce the heightof the vehicle before an underpass/bridge or in order to increase thefloor clearance; adjusting the superstructures and overhangs, forexample retracting the tailgate, turning crane superstructures at bends,adjusting the length of the drawbar).

The system according to the invention provides a high degree ofreliability in preventing collisions as not only the current distancevalues between parts of the vehicle and obstacles is taken into account,but also dynamic changes are sensed and used for a calculation inadvance so that a collision warning can be issued before criticaldistances are reached in the first place. This early warning generallypermits collisions to be prevented through normal driving maneuvers,i.e. inter-ventions by the driver may be made without excessively hastyactions during which there is always the risk of an incorrect reaction(elimination of the so-called reaction time).

In addition to this important aspect of a relatively early warningindication, the system according to the invention can additionallyprovide the driver with valuable information (for example anticipatedlocation of a collision, current distance from the obstacle, remainingtime, etc.), which significantly reduces the reaction time further asthe driver can intervene directly in an entirely targeted fashion. Thissupport is particularly advantageous in unclear situations (unfavorablelight conditions, for example due to fog, driving area with poorvisibility, high traffic volume, etc.) in which the potential risk of acollision is correspondingly high. As not only the driver's own changesin position are taken into account, but also the continued movement ofother road users is detected, it is possible, for example, even todetect an imminent collision which is not brought about by the driver'sown movement (under certain circumstances even in a stationary state)but rather for example as a result of another vehicle approaching.

In addition to the described warning and notification function, thesystem can be configured in such a way that it actively supports thedriver in making difficult maneuvers (narrow course of a road, bridges,and the like). Such help may consist, for example, in the fact thatmovable parts of a vehicle which are at risk of a collision areautomatically removed (swung away, folded in, lowered, etc.) from thearea of risk during maneuvering by the system intervening. The driver isthus largely relieved of the need to perform these various actuationprocesses. Wider-ranging interventions in order to provide support incarrying out maneuvers in spatially restricted conditions are alsopossible. For example, given an appropriate configuration the systemcan, for example, actively change the maneuvering properties of thevehicle (ride control, adjustment of the length of the drawbar, etc.).

In one preferred embodiment to the system according to the invention,the system intervenes directly in the control of the vehicle (steering,brake etc.) in driving situations with critical timing. This providesadditional security in situations in which human reaction times are nolonger sufficient.

The described system for preventing collisions provides the advantagethat it can relatively easily be adapted to changes, for example, in thecontours of a vehicle (for example new trailer, differentsuperstructures etc.). Such changes can be incorporated into the systemwithout a large degree of technical expenditure in that thecorresponding data relating to the new dimensions is simply input intothe memory of the (mobile and/or fixed) data processing system. Given anappropriate embodiment, this can also be carried out, for example, in awire-free fashion. If there are frequently repeated (identical) changes(for example, traveling with a loaded or unloaded container), aplurality of different contours or dimensions of the vehicle may also becontained in the memory of the data processing system and retrieved.

The system according to the invention is defined by a large field of useas it is suitable for a very large range of types of vehicle forpreventing collisions: for example passenger cars with recreationaltrailers, articulated trucks, construction site vehicles (concretemixers, vehicle-mounted cranes, excavator transporters) as well asagricultural vehicles and other utility vehicles.

1. A method far preventing a vehicle colliding with obstacles,comprising (a) calculating in a first step the driving space requiredfor maneuvering of the vehicle by entering into a memory associated witha computer the current dimensions, configuration, and turningcharacteristics of the vehicle including any structure carried on thevehicle and trailer connected to the vehicle, wherein more than oneconfiguration of the vehicle is pre-programmed into said memory andavailable for recall, (b) continuously updating the required drivingspace using sensors associated with at least one of steering wheelposition, vehicle carried structure position, and trailer angle relativeto the vehicle, (c) sensing in three dimensions the distance between thevehicle and both fixed and moving obstacles in the vehicle'ssurroundings, (d) creating in the computer a model of the availabledriving space based on the product of step (a) and (b) as well as storedor sensed road information and the sensed distance values to fixed andmoving obstacles from step (c), (e) sensing instantaneous valuesrelating to the movement, including at least one of speed, direction oftravel, and acceleration/deceleration of the vehicle, (f) calculating,from the product of steps (a)—(e), the driving space required tocontinue safe movement of the vehicle, (g) carrying out a comparisonbetween the existing driving space as determined in steps (a) and (b)and the required driving space calculated in step (f), and (h)initiating via the computer measures for preventing collisions when therequired driving space extends beyond the existing driving space.
 2. Themethod according to claim 1, further comprising transmitting the valuesof the dimensions of the vehicle in wire-free fashion into the memory ofthe computer.
 3. The method according to claim 1, wherein in addition tothe dimensions of the vehicle, features which influence drivingcharacteristics, including at least one of turning radius, swinging outof projecting or towed pans, including at least one of the position ofthe axles within the vehicle and the position and length of a drawbarare included in the calculation of the required driving space.
 4. Themethod according to claim 1, wherein in the case of moving vehicle pansinformation relating to the current position of these vehicle parts isincluded in the calculation of the required driving space.
 5. The methodaccording to claim 1, wherein the required driving space and existingdriving space are calculated at time intervals (t₀, t_(j), t₂, . . . ),these intervals following one another in such brief succession thatchanges to the existing driving space and of the required driving spaceare sensed with appropriate speed so that measures initiated when thereis a risk of collision are designed to prevent a collision.
 6. Themethod according to claim 1, wherein a spatial margin of safety betweenthe vehicle and obstacles is included by at least one of correspondinglyreduced dimensions of the existing driving space and enlarged dimensionsof the required driving space are used to carry out the comparison. 7.The method according to claim 1, wherein the measures initiated toprevent collisions include at least one of: triggering of warningsignals, changing the dimensions of the vehicle, changing themaneuverability of the vehicle, and intervening in the control of thevehicle.
 8. The method according to claim 1, wherein the measures forpreventing collisions are initiated in a sequence which is determined bythe time remaining prior to a collision.
 9. An apparatus for carryingout a method for preventing a vehicle colliding with obstacles, themethod including the steps 0f (a) calculating in a first step thedriving space required for maneuvering of the vehicle by entering into amemory associated wit a computer the current dimensions, configuration,and turning characteristics of the vehicle including any structurecarried on the vehicle and trailer connected to the vehicle, whereinmore than one configuration of the vehicle is pre-prograrmmed into saidmemory and available for recall, (b) continuously updating the requireddriving space using sensors associated with at least one of steeringwheel position, vehicle carried structure positionig, and trailer anglerelative to the vehicle, (c) sensing in three dimensions the distancebetween the vehicle and both fixed and moving obstacles in the vehicle'ssurroundings, (d) creating in the computer a model of the availabledriving space based on the product of step (a) and (b) as well as storedor sensed road information and the sensed distance values to fixed andmoving obstacLes from step (c), (e) sensing instantaneous valuesrelating to the movement, including at least one of speed, direction oftravel, and acceleration/deceleration of the vehicle, (f) calculating,from the product of steps (a)—(e), the driving space required tocontinue safe movement of the vehicle, (g) carrying out a comparisonbetween the existing driving space as determined in steps (a) and (b)and the required driving space calculated in step (f), and (h)initiating via the computer measures for preventing collisions when therequired driving space extends beyond the existing driving space, theapparatus comprising: a memory for storing values of dimensions of thevehicle, and for storing a plurality of different vehicle contours orconfigurations, means for sensing distance values between vehiclecomponents and obstacles in surroundings of the vehicle, means forsensing movement parameters of die vehicle, including at least one ofspeed, direction of travel and acceleration/deceleration of the vehicle,a data processing system for calculating an existing driving space fromthe distance values, means for additionally calculating, from themovement parameters in conjunction with the values of the dimensions ofthe vehicle, a driving space which is required to continue driving, andmeans for carrying our a comparison between the existing driving spaceand the required driving space, and mechanism for being actuated by thedata processing system in order to prevent a collision when thecalculated required driving space expands beyond the existing drivingspace wherein the data processing system is associated with the memory.10. The apparatus according to claim 9, further comprises acommunications unit for transferring the values of the dimensions of thevehicle can be transferred into the memory of the data processing systemin a wire-free fashion.
 11. The apparatus according to claim 9, whereinthe data processing system also includes, in the calculation of therequired driving space, information relating to the structuralproperties of the vehicle, which also determine a driving behavior ofthe vehicle.
 12. The apparatus according to claim 9, further comprisesmeans which, in the case of moving pans of the vehicle, sense a currentposition of these parts of the vehicle vehicles and these values areincluded in the calculation of the required driving space by the dataprocessing system.
 13. The apparatus according to claim 9, wherein thedata processing System determines the required driving space and theexisting driving space at time intervals (t₀, t₁, t₂, . . . ) whichfollow one another in such short succession that changes to the existingdriving space and to the required driving space are sensed withappropriate timeliness so that the devices mechanism for preventing acollision is actuated by the data processing system at such an earlytime that a collision is prevented.
 14. The apparatus according to claim9, wherein a spatial safety distance between the vehicle and obstaclesis included by virtue of the fact that, before the comparison is carriedout, the data processing system at least one of reduces the dimensionsof the existing driving space by computational means or increases thedimensions of the required driving space.
 15. The apparatus according toclaim 9, wherein the mechanism for preventing a collision includes atleast one of: means for triggering warning signals means for changingthe dimensions of the vehicle means for changing the maneuverability ofthe vehicle means for intervening in the control of the vehicle.
 16. Theapparatus according to claim 9, wherein the mechanism for preventing acollision is prioritized by the data processing system and carried outin a sequence which is determined by the time remaining prior to acollision.
 17. The apparatus according to claim 9, wherein the means forsensing distance values between parts of a vehicle and obstacles areembodied as optical or audible, distance measuring sensors or asradiation sensors or as video cameras or as electronic devices fordetermining position or environment.
 18. The apparatus according toclaim 9, wherein the data processing system is carried in the vehicle asa mobile system.
 19. The apparatus according to claim 9, wherein thevehicle is connected to a stationary data processing system via awire-free connection.
 20. The method according to claim 1, wherein thevalues of the dimensions of the vehicle are read out of a memory, whichis configured for simultaneously storing a plurality of differentvehicle contours.